6. Roberto Di Matteo Sacked, Rafael Benitez Appointed

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Even though his playing career had already made him a legend at Stamford Bridge, when Roberto Di Matteo was fired from his position as Chelsea manager, it was more than just the Chelsea fans who were shocked.

After all, Di Matteo had brought the Blues their first Champions League trophy in the history of the club just months before.

Add to this the selection of Chelsea fans' least favorite manager as his replacement, and you have a moment that is still causing outrage months later.

2. Champions League Semifinal 2009

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After an exciting two legs of football, there were two things that made this the second most painful moment in the last decade for Chelsea fans.

The first is the excruciating nature of the goal that put them out. Chelsea were on their way to the Champions League final until the third minute of stoppage time, when Andres Iniesta pulled off a wonder strike that would send them crashing out with no time to respond.

The second is that Chelsea had an astonishing number of penalty appeals denied throughout the match, at least four of which were quite clear cut. Yet no penalties were awarded, and Barcelona sent the Blues home yet again.